Audit a page for next/image misuse before Lighthouse catches it

<context>
Page or component code to audit: app/blog/[slug]/page.tsx — hero image plus inline images in the post body
External image domains in use, if any: images.ctfassets.net (Contentful), cdn.example-cms.com
</context>

<task>
Audit every image on this page for next/image correctness. Flag anything using a plain <img> tag where next/image should be used, and anything using next/image incorrectly in a way that would hurt Core Web Vitals.
</task>

<checklist>
- Plain <img> tags for content images: flag for conversion to next/image, unless there's a specific reason (e.g. an SVG icon, or an image whose dimensions genuinely can't be known ahead of time) — name that reason if you're leaving one as-is.
- The largest above-the-fold image (the likely LCP element): must have priority set to disable lazy-loading; if it's currently lazy-loaded by default, that's a direct LCP regression, flag it as high severity.
- Every other next/image usage: should NOT have priority set — marking every image priority defeats the point and front-loads bandwidth for images the user may never scroll to.
- Any image using fill: confirm its parent element has position: relative (or similar) and defined dimensions; fill with an unsized/static parent causes the image to collapse or overflow.
- Any image using explicit width/height instead of fill: confirm the values match (or are proportional to) the actual source image's aspect ratio — mismatched dimensions cause layout shift or a distorted image.
- Any image sourced from an external domain: confirm that domain is in next.config's images.remotePatterns; flag any that aren't — those requests fail at request time in production, not at build time, so this often only surfaces after deploy.
- Images that resize significantly across breakpoints (e.g. full-width on mobile, one-third width on desktop): confirm a sizes attribute is set so the browser downloads an appropriately sized file at each breakpoint, not the largest variant everywhere.
</checklist>

<output_format>
A findings table: Image/location | Issue | Severity (LCP-impacting / CLS-impacting / will-fail-in-prod / minor) | Fix.
</output_format>